Conductive human electrical terminal

ABSTRACT

A slip-on conductive rubber boot or overshoe has toe, heel and side sections which come up over a worker&#39;&#39;s shoe far enough to insure a good electrical contact between the human wearing the boot or overshoe and ground, regardless of the body position. An integral conductive rubber strap extends from the boot or overshoe upwardly toward a garter for encircling the leg above the calf. A comfortable connector on the garter insures the snug, but not tight fit of the garter. There are no snaps to unsnap, no buckles to dig in, no loose parts to become lost.

' United States Patent Young Oct. 14, 1975 CONDUCTIVE HUMAN ELECTRICALTERMINAL [76] Inventor: David Arthur Young, 1 130 Surrey,

Glen Ellyn, 111. 60137 [22] Filed: Jan. 14, 1974 [21] Appl. No.: 433,213

[52] US. Cl 317/2 B [51] Int. Cl. HOSF l/00; HOSF 3/02 [58] Field ofSearch 317/2 B [56] References Cited UNITED STATES PATENTS 2,287,7446/1942 Monahan 317/2 B 3,281,624 10/1966 Patchen..... 317/2 B 3,459,9978/1969 Legge 317/2 B Primary ExaminerL. T. Hix Attorney, Agent, orFirm-Alter and Weiss ABSI'RACT A slip-on conductive rubber boot 0rovershoe has toe, heel and side sections which come up over a workersshoe far enough to insure a good electrical contact between the humanwearing the boot or overshoe and ground, regardless of the bodyposition. An integral conductive rubber strap extends from the boot orovershoe upwardly toward a garter for encircling the leg above the calf.A comfortable connector on the garter insures the snug, but not tightfit of the garter. There are no snaps to unsnap, no buckles to dig in,no loose parts to become lost.

4 Claims, 7 Drawing Figures CONDUCTIVE HUMAN ELECTRICAL TERMINAL Thisinvention relates to electrical terminals for the human body and moreparticularly to safe, reliable, and comfortable means for maintaining adesired body potential.

There are many times when and places where it is desirable to maintain acertain body potential, usually a ground potential. For example, personsmoving through an explosive laden atmosphere (such as a hospitaloperating room filled with ether fumes) often wish to maintain a bodyground potential and thereby avoid static electricity sparks. Somemedical treatment may involve an application of electrical currents tothe body. Workers in intense electrical fields, such as extremely highvoltage power line towers, must be grounded at all times for theirsafety. Those familiar with the field will readily perceive many othertimes and places when a human terminal is either necessary or desirable.

For example, a worker on a high voltage tower is in an extremely highvoltage field wherein his ungrounded body would receive ambient energyin a volume and level comparable to the energy that is consumed by asoldering iron. His body coupling into this electrical environment iscapacitive, and therefore, this energy is accumulated as a charge on hisbody, much as a charge is built upon a capacitor. When the chargingenergy reaches a sufficient level, there is a discharge in the nature ofa static electric are between the body and ground. The body effectproduced by such discharge is most difficult to predict. There could bea muscular spasm causing a part of the body to jerk, which could resultin a fall or the touching or clutching of a high voltage source; or, theheart muscle could be affected to cause death.

The body charge will not build up if the body is held at the potentialof the system ground. Accordingly, it is common practice for people inthis kind of environment to wear conductive boots or overshoes whichform ground terminals for the body. These ground terminals must maintaina continuous contact with the system ground, at all times. Therefore,the best boots or overshoes are those which make good contact regardlessof how the worker moves, whether he is standing or lying prone, on hisface, back or side. Also, since the worker climbs over tower struts,bolt heads, screw ends, and the like, the boots or overshoes must resistsnagging and tearing which would reduce reliability.

Usually, the boots or overshoes are electrically connected directly tothe workers body so that the skin potentials will flow off the body andonto the boots or overshoes. Often the body contacts are garters aroundan arm or leg, or a belt around the waist. These garters or belts mustmake good skin contact, yet they must be comfortable. If the garter orbelt is too tight, it could cut off circulation. If too loose, it couldmake an inefficient electrical contact with the body. If there are snapsor buckles, they could come unsnapped, dig into the body, or otherwisebecome very uncomfortable.

Accordingly, there is a need for a-conductive boot or overshoe whichresists wear, tear and other similar damage, which is comfortable to useand which maintains contact with ground, regardless of the workers bodyposition.

Therefore, an object of the invention is to provide new and improvedbody terminals. Here an object is to provide conductive boots orovershoes which are easy to put on or take off over normal workers bootsor shoes. Another object is to provide conductive boots or overshoeshaving integral body contacts which are positive in operation andcomfortable in use. Still another object is to provide conductive bootsor overshoes which are free of loose parts that might tend to unsnap orbecome lost.

Another object is to provide conductive boots' or overshoes of a shapeand design which is always in contact with a ground surface despite manychanges in body position.

Still another object of the invention is to provide conductive boots orovershoes which are less likely to become torn or otherwise damaged fromcontact with towers, struts, bolt heads or the like.

In keeping with an aspect of this invention, these and other objects areaccomplished by providing a slip-on conductive rubber boot or overshoehaving an arch strap to help secure it in place. The toe, heel and sidesof the boot or overshoe come up over a worker's shoe far enough toinsure a good electrical contact between the boot or overshoe and groundregardless of the workers body position. An integral strap of conductiverubber extends from the boot or overshoe upwardly. It terminates in agarter for encircling the leg above the calf. A special mechanicalconnector on the garter insures a snug, but not tight, comfortable fit,without the possibility that the garter will come unfastened. There areno snaps to unsnap, no buckles to dig in, no loose parts to become lost.

The nature of a preferred embodiment of the invention will become moreapparent from a study of the attached drawings wherein:

FIG. 1 is a perspective view of the inventive boot or overshoe as wornby a worker;

FIG. 2 is a plan view of the boot or overshoe with the integralextension and garter;

FIG. 3 is a cross-sectional view of FIG. 1 taken along line 33 thereof,showing how the boot or overshoe follows the contours of the shoe, toe,sole and heel;

FIG. 4 is a fragmentary view of the tread pattern on the bottom of theboot or overshoe; and

FIGS. 5-7 are three stop motion views showing the use of the fastenerattached to the garter.

In greater detail, the inventive boot or overshoe 20 comprises a toe cap21, a heel section 22 and an arch strap 23, integrally interconnected byside members 24, 25 and sole 26. The toe cap 21 raises from the sole andcovers a sufficient area on the top and sides of the worker's toes toinsure a good contact with ground regardless of how the worker lies onhis stomach or bends his ankle. Likewise, the heel section 22 comes uparound the back and heel sides of the workers heels with similar effectwhen the worker lies on his back. The side panels 24, 25 integrallyinterconnect toe cap 21 and heel section 22 for making a similar contactwith ground, while the worker is lying on his side. From this, it shouldbe apparent that, regardless of the workers body position, the boots orovershoes on his feet are always in good electrical contact with theground, at all times.

The boots or overshoes are shaped and dimensioned to resist wear,tearing and the like; yet they are easy to slip on or remove. Moreparticularly, as best seen in FIG. 3 the boot or overshoe fits over theworkers regular shoe or boot snugly enough to resist bagging orwrinkling while being worn. The heel area 30 of the boot or overshoecomes up and around the heel 31 of the workers regular shoe or boot 32to preclude any looseness in the instep area, where a bolt head mightotherwise catch loose material. The ankle strap 23 easily slips on overthe arch of the foot, and yet it also pulls the side walls 24, 25 uptightly against the shoe.

From FIGS. 1, 3 and 4, it is seen that the tread design 32 of the bootor overshoe sole is sufficiently thick to resist wear. It is shaped toguide the contact area of the foot over or around bolt heads 33, nuts,struts and the like whereby minor obstacles fit into spaces 35 in thetread, between the fins 36, 37.

Integrally molded with the boot or overshoe is an extension member 38which raises from the boot or overshoe toward the workers knee. At thetop of extension 38 is a leg encircling garter 40 shaped and dimensionedto fit around the leg in the area lying generally between the knee andcalf. This garter fits against the workers skin to make good bodycontact.

The coupler on the garter is a reliable device which insures a snug fitaround the leg, without being too tight. This is important since thesnug fit insures good electrical contact with the body, while the nottoo tight fit insures continued blood circulation.

FIGS. -7 show how the coupler is designed and operated-One end 41 of thegarter 40 includes a series of belt holes 46 spaced from each other bydistances which enable a worker to select a comfortable length. Theother end 47 of the garter has an upstanding post 48 formed in threesections. Section 49 is a somewhat rod-like member which fits through ahole 46 and projects far enough on the other side of garter 40 for aworker to grip and pull it. The next post section 50 is conical andshaped to guide the selected hole 46 into a stretched configuration. Thesoft conical rubber of section 50 tends. to compress somewhat as thehole stretches around it. The last section 51 on post 48 isapproximately the same diameter as the hole 46. Therefore, the belt holetends to snap around section 51.

Thus, to attach the garter, the worker selects a belt hole and projectsthe rod end 49 through it (FIG. 5). Then he grips end 49 and pushes thebelt hole 46 down over the conical section 50 (FIG. 6). Finally, hesnugs the belt end with the selected hole 46 captured under the flaredend of conical section 50 (FIG. 7).

The garter is now in place. The garter is tight enough to insure goodelectrical contact without interfering with the workers circulation. Thepositive catch around conical section 50 will not easily comeunfastened, but can be released by pulling garter end 41. There'are nobuckles to dig into the workers leg. There are no loose parts to comeunsnapped and be lost.

The entire unit may preferably be made from a simple molded piece ofconductive rubber.

While different conductive elastomers may be used to make the boot orovershoe, I prefer to use one known by the American Society of Testingand Measurements Code number 4AA625A13B1'3C12. Of these codes: 4AA is acompounding number, 625 refers to 60 durometer and 2500 pounds persquare inch tensile strength; A13 refers to a heat age; 813" refers to al6 percent compression; and C12 refers to ozone resistance. This codedinformation is summarized in the following'table.

Durometer 60 Tensile 2500 PSI (min) Elongation 400% Oven Aged 96 hrs. at158F ASTM-D-573 at 3l0 (3C) Durometer Change +IO Tensile Change -l5%(max) Elongation Change 20% Compression Set 22 hrs.

l58F ASTM-D-395 Method B 25% Ozone 72 hrs. at SOPPHM at lO0F ASTM-D-ll7l & AT8310 (2-E) 0" Rating Those skilled in the art will readilyperceive modifications and improvements; therefore, the appended claimsare to be construed to cover all equivalents falling within the scopeand spirit of the invention.

I claim:

1. A conductive electrical terminal comprising a slipon conductive bootor overshoe,

said boot or overshoe having a conductive sole, toe

vamp, heel vamp and side vamp sections,

said toe vamp section comprising toe vamp cap,

said toe vamp cap having a horizontal portion covering the top fromsection of the users shoe,

said heel vamp section comprising a member which comes up around theback and sides encircling the heel of a shoe, and the side vamp sectionrising above the sole and welt sections of the users shoe, whereby saidvamp sections come up over the users shoe far enough to insure a goodelectrical contact between the boot or overshoe and ground regardless ofthe users body position,

an integral conductive strap means extending from the heel area of theboot or overshoe upwardly,

a garter integrally and electrically connected to said strap forencircling the leg of the user below the knee and above the calf,

mechanical connector means on the garter to insure a snug, but nottight, comfortable fit around the users leg without requiring tying,

one end of the garter includes a series of belt holes spaced from eachother by distances which enable a user to select a comfortable length,

the mechanical connector on the garter is an upstanding post on theother end of the garter,

said post being formed in three sections,

one section being a somewhat rod-like member which fits through a holeand projects far enough on the other side of the garter for a worker togrip and pull it,

the next post section being conically shaped,

the last section being a post approximately the same diameter as a hole,and

said boot or overshoe strap and garter being free of snaps, buckles andloose parts.

2. The terminal of claim 1 wherein said conductive boot or overshoe andstrap are a single integral member made of conductive rubber.

3. The terminal of claim 2 wherein the conductive rubber has thefollowing characteristics:

Durometer 60 Tensile 2500 PSI (min) Elongation 400% Oven Aged 96 hrs. at158F ASTM-D-573 at 3l0 (3C) Durometer Change +l0 -Continued TensileChange Elongation Change Compression Set 22 hrs.

158F ASTM-D-395 Method B Ozone 72 hrs. at SOPPHM at lF ASTM-D-l l7l &AT83l0 (2-E) -l5% (max) "0" Rating.

into spaces in the tread.

1. A conductive electrical terminal comprising a slip-on conductive boOtor overshoe, said boot or overshoe having a conductive sole, toe vamp,heel vamp and side vamp sections, said toe vamp section comprising toevamp cap, said toe vamp cap having a horizontal portion covering the topfront section of the user''s shoe, said heel vamp section comprising amember which comes up around the back and sides encircling the heel of ashoe, and the side vamp section rising above the sole and welt sectionsof the user''s shoe, whereby said vamp sections come up over the user''sshoe far enough to insure a good electrical contact between the boot orovershoe and ground regardless of the user''s body position, an integralconductive strap means extending from the heel area of the boot orovershoe upwardly, a garter integrally and electrically connected tosaid strap for encircling the leg of the user below the knee and abovethe calf, mechanical connector means on the garter to insure a snug, butnot tight, comfortable fit around the user''s leg without requiringtying, one end of the garter includes a series of belt holes spaced fromeach other by distances which enable a user to select a comfortablelength, the mechanical connector on the garter is an upstanding post onthe other end of the garter, said post being formed in three sections,one section being a somewhat rod-like member which fits through a holeand projects far enough on the other side of the garter for a worker togrip and pull it, the next post section being conically shaped, the lastsection being a post approximately the same diameter as a hole, and saidboot or overshoe strap and garter being free of snaps, buckles and looseparts.
 2. The terminal of claim 1 wherein said conductive boot orovershoe and strap are a single integral member made of conductiverubber.
 3. The terminal of claim 2 wherein the conductive rubber has thefollowing characteristics:
 4. The terminal of claim 1 wherein said solehas a tread design sufficiently thick to resist wear and shaped to guidethe contact area of the foot over bolt heads, nuts, struts and the likewhereby minor obstacles fit into spaces in the tread.